Bug 14407 - Fn + brightness up/down keys doesn't work if ACPI enabled - Samsung NC20
Summary: Fn + brightness up/down keys doesn't work if ACPI enabled - Samsung NC20
Status: RESOLVED PATCH_ALREADY_AVAILABLE
Alias: None
Product: Drivers
Classification: Unclassified
Component: Input Devices (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: drivers_input-devices
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-10-14 22:17 UTC by Barry Carroll
Modified: 2009-10-14 22:52 UTC (History)
1 user (show)

See Also:
Kernel Version: 2.6.31
Subsystem:
Regression: No
Bisected commit-id:


Attachments
Patch to stop the N130 generating repeated key events (629 bytes, patch)
2009-10-14 22:17 UTC, Barry Carroll
Details | Diff
lspci -v output (5.42 KB, text/plain)
2009-10-14 22:19 UTC, Barry Carroll
Details
dmesg output (42.86 KB, text/plain)
2009-10-14 22:20 UTC, Barry Carroll
Details

Description Barry Carroll 2009-10-14 22:17:14 UTC
Created attachment 23413 [details]
Patch to stop the N130 generating repeated key events

Hi, this is a bug similar to the NC20 patch that I submitted previously.  The N130 is a new machine and there is also an N140 which will probably also have the problem but I do not have that machine to test.

Distribution: Ubuntu Karmic Beta
Kernel: 2.6.31-13-generic

Prerequisites
=============
This bug will not manifest unless the udev or hal has been configured to recognise the laptop.

Steps to reproduce:
===================
Press fn key plus up arrow to increase brightness, press fn key plus down arrow
to decrease brightness

Expected results
================
Screen brightness is increased or decreased 

Actual results
==============
fn plus down arrow reduces brightness to minimum.
fn plus up arrow increases brightness to maximum.
Gnome interface becomes unusable: menus cannot be clicked, keyboard becomes
unresponsive

Workaround
==========
The user can switch to a VT and then back to the GUI and this allows normal keyboard operation until they press fn+up or fn+down again.

Comments
========
The behaviour observed is because the key release events after brightness up
and brightness down are not generated.  This has the effect of repeating the
brightness up or brightness down keys indefinitely.  This causes the "all or
nothing" effect on brightness and the unresponsive Gnome GUI.
Comment 1 Barry Carroll 2009-10-14 22:19:27 UTC
Created attachment 23414 [details]
lspci -v output
Comment 2 Barry Carroll 2009-10-14 22:20:09 UTC
Created attachment 23415 [details]
dmesg output
Comment 3 Barry Carroll 2009-10-14 22:22:58 UTC
I will be creating a linked bug report downstream in Ubuntu.  I have tested a kernel with the patch and it works as expected.

Signed-off-by: Barry Carroll <baz8080@gmail.com>
Comment 4 Dmitry Torokhov 2009-10-14 22:49:46 UTC
There is now a way to control force release mask from userspace, no more patches will be accepted for the kernel. See bug 14052.
Comment 5 Barry Carroll 2009-10-14 22:52:53 UTC
Thanks Dmitry, I'll check it out.

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